1. Field of Invention
The present invention relates to fluid displacement apparatus of the kind comprising relatively rotatable parts which, on relative rotation occurring, causes fluid to move.
2. Description of Related Art
The invention is particularly concerned with the suspension of the rotatable parts especially in a gas turbine engine compressor. Present day gas turbine engine technology includes shafts which rotate within fixed structure, and are supported therefrom via ball and roller bearings. The support mode necessitates the use of oil pumps, galleries, scavenge pumps, oil coolers and reservoirs, which adds considerably to design complexity, weight and cost. Consequently, the present invention seeks to provide gas turbine engine fluid displacement apparatus, which obviates that need in toto.
According to the present invention, gas turbine engine fluid displacement apparatus comprises a ring and a drum, the ring being held co-axially with and around the drum by a circular array of blades, the ring being magnetically permeable, and In turn surrounded by a casing, through which a circular array of electromagnetic stators comprising wire wound poles protrude, a stator power supply, and sensors for sensing the magnitude of any gap between the stators and ring, and generating signals therefrom, and control means connected between said sensors and said stator power supply, so as to receive any said signals and so cause said power supply to power one or more stator windings in a manner which will result in one or more stator poles generating sufficient magnetism across appropriate gaps as to cause the fluid displacement apparatus to adapt a position wherein said ring is equidistant from all said stator poles.
The invention will now be described, by way of example and with reference to the accompanying drawings in which: